1. Field of the Invention
The present invention relates to a photoelectric converter connecting device to be used for transmission or reception in optical communication using optical fibers.
2. Description of the Related Art
Index distribution type lenses or ball lenses have been used for photoelectric converter connecting devices for optical communication. In recent years, aspherical lenses have begun to be used for the improvement of coupling efficiency and the stabilization of lens performance in removing the spherical aberration of the above-mentioned lenses. Furthermore, for the improvement of lens handling, aspherical glass lenses being unified with lens-barrels in molding process can be found in the market. In FIG. 4, a conventional example is shown, and in the figure, 11 is a photoelectric converter, 12 is an elastic sleeve, 13 and 14 are holders, 15 and 16 are lens-barrels and 17 is an index distribution type lens. The index distribution type lens 17 is pressed into a lens-barrel or stuck to it with low melting point glass for the improvement of lens handling. The dispersion in optical characteristics of index distribution type lenses 17 is large, and the lens-barrel 15 and the lens-barrel 16 are fixed to each other with adhesive after the direction of the optical axis of the lens-barrel 15 is mechanically adjusted in sliding the lens-barrel for the end surface D of the lens-barrel to be abutted against the end surface of an optical fiber ferrule ( not shown in a drawing) or after the confirmation and adjustment of optical characteristics in some manufacturing lots of the index distribution type lenses 17. The lens-barrel 16 and the holder 14 are fixed to each other by laser welding on a junction surface Y3. Next, the holder 14 and another holder 13 being incorporated with the elastic sleeve 12 are fixed to each other by laser welding on a junction surface Y4, and a receptacle 18 with a lens is completed. Further, the photoelectric converter 11 driven in a state where an optical fiber is inserted into the elastic sleeve 12 in a position abutting against the end surface D is incorporated into the holder 14, and the photoelectric converter 11 is adjusted being moved in the direction perpendicular to the optical axis in a state where it is abutted against the holder 14, and the photoelectric converter 11 and the holder 14 are fixed to each other on the junction surface Y5 by laser welding at a position where the optimum optical coupling efficiency can be obtained, and the optical system being composed of the optical fiber, the index distribution type lens 17 and the photoelectric converter 11 is maintained stably.
It may be possible to make some improvements partially in a conventional constitution; however, there has been a problem that the number of parts becomes large for the adjustment of the characteristic of an index distribution type lens and also that the mandays for fixing these parts become large.